Method of forming a volute spring



April 6, 1937. H, A, KN'OX 2,075,815

METHOD OF FORMING A VOLUTE SPRING Filed Sept. 29, 1954 invents? H215 A-KMX AfL L m ney Patented Apr. 6, 1937 I UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a method of forming a volute spring.

The purpose of the invention is to provide a method of forming a volute spring which will enable the spring to be made of alloy steel. Since alloy steel requires uniform quenching. during tempering the present method consists generally in insuring the provision of a thin space between the coils by initially placing therebetween a thin sheet oil a material which is subsequently melted out or consumed.

The improved method is illustrated in the accompanying drawing, in which,

Fig. 1 is a plan view of a volute spring including a liner.

Fig. 2 is a longitudinal sectional view of a volute spring when rolled with the liner.

Fig. 3 is a similar view with the liner between the coils removed. I

Referring to the drawing by characters of reference, the volute spring is formed by rolling a steel plate 5 into a spiral coil in the usual manner. A thin sheet 6 of aluminum, brass, or other low melting material is placed on the inside of the plate 5 so that it forms a liner between the convolutions oi the coil as shown in Fig. 1.

The spring is now heated to melt out or consume the liner which on being removed provides a thin space 1 between the convolutions of the coil. The spring is now tempered by heating and quenching, the cooling liquid coming in con 5 tact with all surfaces of the spring.

I claim:

1. The method of forming a volute spring which consists in placing a thin sheet of low melting material on the inside of a plate, rolling 10 the plate into a spiral coil, melting the thin sheet to cause its removal and leave a space between the convolutions of the coil, and then tempering the coil.

2. The method of forming a volute spring which 15 consists in placing a thin sheet of low melting material on the inside of aplate, rolling the plate into a spiral coil, melting the thin sheet to cause its removal and leave a space between the convolutions of the coil. 2O

3. The method of forming a volute spring which consists in rolling a plate with a liner into a spiral coil, removing the liner to leave a space between the convolutions of the coil, and then tempering the coil. 25

4. The method of forming a volute spring which consists inrolling a plate with a liner into a spiral coil, and removing the liner to leave a space between the convolutions of the coil.

HARRY A. KNOX. 

